<%@ page language="java" contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>Insert title here</title>
</head>
<body>
<jsp:useBean id="calculater" scope="request" class="com.example.javabeantest.javaBeanSamples.calculater"></jsp:useBean>
<jsp:setProperty property="*" name="calculater"></jsp:setProperty>
<form action="index2.jsp" method="get">
    <hr align="left" style="width: 400px;">
    计算结果是：
    <span>
        <%
            if (request.getParameter("operator") != null){
                String operator = request.getParameter("operator");
                int oper = Integer.parseInt(operator);
                if(oper == 4 && calculater.getNum2() == 0){
                    out.print("出错，除数不能为零！");
                }else {
        %>
        <%=calculater.getNum1()%>
        <%
            if (oper == 1) out.print("+");
            if (oper == 2) out.print("-");
            if (oper == 3) out.print("*");
            if (oper == 4) out.print("/");
        %>
        <%=calculater.getNum2()%>
        =
        <%=calculater.getResult()%>
        <%
                }
            }
        %>
    </span>
    <!--表达式显示-->
    <hr align="left" style="width: 400px;">
    <div align="left" style="width: 400px;">
        <p align="center">简单计算器</p>
        第一个参数：<input type="text" name="num1"/><br>
        <div style="padding-left: 100px;">
            <select name="operator">
                <option value="1">+</option>
                <option value="2">-</option>
                <option value="3">*</option>
                <option value="4">/</option>
            </select>
        </div>
        第二个参数：<input type="text" name="num2"/><br>
        <input type="submit" value="计算" style="margin-left: 100px;"/>
    </div>
</form>
</body>
</html>
